Carbon nanodots, Ru nanodots and hybrid nanodots: preparation and catalytic properties

Abstract

New hybrid nanodots comprised of carbon nanodots and ruthenium nanodots have been synthesized from peptide functionalized carbon nanodots and a ruthenium salt. At first, carbon nanodots have been prepared by carbonization of a synthetic tripeptide and citric acid. Then these functionalized carbon nanodots act as a template to form ruthenium nanodots from a ruthenium salt in the presence of a reducing agent, sodium borohydride in water medium. These functionalized carbon nanodots exhibit a blue emission with a high quantum yield (69.8%). Various techniques including UV-Vis, fluorescence, FTIR, X-ray photoelectron spectroscopy (XPS), Raman and X-ray diffraction and transmission electron microscopy (TEM) analyses have been used to characterize carbon nanodots and hybrid nanodots. This is a new example of preparing ruthenium nanodots by using peptide functionalized carbon nanodots as a stabilizer to form unique hybrid nanodots consisting of carbon nanodots and ruthenium nanodots in water medium. Moreover, hybrid nanodots act as a potential catalyst for the reduction of organic azides to their corresponding amines in aqueous medium. A variety of functionalized organic azides have been reduced to their corresponding amines with high yields without affecting other functionalities indicating the good chemoselectivity of the catalyst towards the azide functionality.